1. Field of the Invention
The present invention relates to a rotary push switch mainly used in a vehicle interior light, and more particularly to a rotary push switch in which its components are simply assembled so as to maximize its assembling efficiency and productivity, and which provides a firm contact between fixed terminals and a movable terminal, and various connections of wirings so as to maximize its convenience in use.
2. Description of the Related Art
Generally, a conventional push switch comprises in combination a push button, an actuator, a movable terminal, a carrier, and a plurality of fixed terminals, installed between an upper housing and a lower housing.
In such a conventional push switch, whenever the push button is pressed and then returned to its original position, the actuator installed under the push button is operated to serve as a cam mechanism so that the carrier is intermittently rotated together with the movable terminal and selectively contacts the plural fixed terminals installed below the movable terminal, thus allowing the push switch to be turned on/off.
Several types of the push switch are disclosed by U.S. Pat. No. 4,891,476, and Korean Utility Model Registration Publication Nos. 198345 and 207503 to the present inventor(s).
More specifically, the assembled structure of one of the above disclosed conventional push switches is obtained by assembling a push button, an actuator, a return spring, a movable terminal, and a carrier in sequence using an assembling hole provided with a guide groove and installed through an upper housing. In both the push button and the actuator, a sliding protuberance formed along each of their peripheral surfaces is inserted into the guide groove of the assembling hole, and simultaneously a driving cam and an interlocked cam with gearwheel shapes are interlocked so that they are simultaneously operated. In the actuator, the carrier obtained by assembling the movable terminal including a plurality of contact portions and the return spring is intermittently rotated by a user""s pushing of the push button.
Further, a substrate provided with a plurality of fixed terminals is assembled below the movable terminal including a plurality of the contact portion into a lower housing. By the rotation of the movable terminal, the plural contact portions of the movable terminal selectively contact the plural fixed terminals, thus allowing the push switch to be turned on/off.
The upper and lower housings are fixed to each other by inserting assembling rods formed on one housing into assembling holes formed on the other housing and then thermally fusing protruded ends of the assembling rods.
Other types of the conventional push switch disclosed by U.S. Pat. No. 4,996,401, and Korean Utility Model Registration Publication Nos. 128963 and 126988 to the present inventors. Compared to the above types of the conventional push switch, each of these types of the conventional push switch comprise movable and fixed terminals having designated shapes being different from the former types. Here, the fixed terminals are inserted into the inner wall of a lower housing, and the movable terminal is in contact with or out of contact with the fixed terminals by the rotation of the movable terminal, thus allowing the push switch to be turned on/off. The essential operating structures of these push switches are the same as or similar to those of the former push switches.
However, the above-described various conventional push switches have several problems, as follows.
First, since the push button, the actuator, the return spring, the movable terminal, and the carrier are assembled into one unit using the assembling hole of the upper housing, that is, many components are simultaneously assembled, the assembling efficiency and productivity of the above conventional push switches are reduced.
Further, since many components are assembled into the upper housing as they are not fixed or supported to one another, when the obtained upper housing and another component (i.e., the lower housing) are assembled, it is difficult to maintain their assembled condition and the assembling process of the above conventional push switches is inconvenient.
Second, since the upper and lower housings are combined by inserting assembling rods formed in one housing into assembling holes formed in the other housing and thermally fusing protruded ends of the assembling rods, the upper and lower housings are fixed to each other via a series of assembling and thermal fusion processes, thus reducing the assembling efficiency of the above conventional push switches.
Particularly, since the thermal fusion process requires expert skill, such a thermal fusion process is prone to cause defects in assembling the above conventional push switches and the assembled conventional push switches cannot be separated into their individual components.
Third, a plurality of the fixed terminals (i.e., three terminals) are independently assembled into the lower housing, thus causing inconvenience in assembling the above conventional push switches.
In order to solve the above third problem, there is proposed a method in which a plurality of the fixed terminals are riveted on a separate substrate and then the substrate provided with the fixed terminals is assembled into the lower housing. However, this method requires a step for fixing the fixed terminals to the separate substrate, thus causing inconvenience in assembling the above conventional push switches.
Fourth, the above conventional push switches are limited in their method of connection to power. That is, a pin-type terminal connected to a power line is inserted into a connection portion at one end of each of the above fixed terminals.
Further, the connection portion includes a hole formed at the end of the fixed terminal and the terminal is tightly fitted with the hole, thus causing inconvenience in assembling the above conventional push switches. Particularly, in case the outer diameter of the terminal does not coincide with the inner diameter of the correspondent hole even if the difference between the diameters is very small, it is difficult to insert the terminal into the hole or even if possible, the terminal is easily released from the hole.
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a rotary push switch in which its components are simply assembled so as to maximize its assembling efficiency and productivity, and which provides a firm contact between a movable terminal and fixed terminals so as to maximize its reliability in use.
It is another object of the present invention to provide a rotary push switch which provides various connections of wirings so as to maximize its convenience in use.
In accordance with the present invention, the above and other objects can be accomplished by the provision of a rotary push switch formed in a built-up manner by assembling upper and lower housings by elastically inserting a plurality of locking protuberances formed along one housing into a plurality of locking grooves formed along the other housing, wherein: a return spring and an actuator are assembled in a carrier within the upper housing, a push button is inserted into an upper part of the carrier provided with the returning spring and actuator, and a movable terminal is inserted into a lower end of the carrier provided with the returning spring and actuator; and a plurality of fixed terminals are integrally formed with the lower housing and soldering holes are formed through a bottom of the lower housing at positions corresponding to the fixed terminals so that a power line is connected to the fixed terminals using terminals or by soldering.